Portable cutting tool



Feb. 15, 1944. F. A. JIMERSoN E'rAL ,2,342,052

PORTABLE CUTTING Tool.

Filed Fb. 21. 1942 90 Il!" www n 3488 25 J3 3:5 27 76' 171 -2 E5 a? rw/79 8974 THEIR ATTORNEY.

Patented Feb. 145, 1944 PORTABLE CUTTING Tool.

Francis A. Jimerson and Harold C. Reynolds,

Athens, Pa., assignors to Ingersoll-Band Company, New York, N. Y., a corporation of New Jersey Application February 21, 1942, Serial No. 431,774

3 Claims. (Cl. 143-43) This invention relates to power driven cutting tools, and more particularly to a portable cutting tool intended for cutting brush, weeds and the like.

One object of the invention is to construct a light-weight, rugged and well balanced cutting tool that may be easily manipulated with respect to the work.

Another object is to prevent deviation of the brush from its normal position during the cutting operation.

A further object is to avoid the occurrence of accidents through contact with the cutting element of the tool.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawing accompanyingy this specication and in which similar reference numerals refer to similar parts,

Figure 1 is a longitudinal side elevation, partly broken away, of a cutting tool constructed in accordance with the practice of the invention,

Figure 2 is a similar view, somewhat enlarged,

showing the cutting disc and the elements serving to transmit /rotary movement to the cutting disc, and

Figure 3 is a top plan view of the cutting tool.

Referring more particularly to the drawing, designates, in general, the casing of a portable cutting tool constructed in accordance with the practice of the invention and 2| a toothed cutting disc housed by the casing .20.

The casing 20 consists of a plurality of parts including a hood 22 and a cover 23 attached to the hood by screws 24. The opposed portions of the hood 22 and the cover 23 are suitably recessed to form a chamber 25 for the accommodation of the cutting disc 2|.

On the outer surface oi" the hood 22 and integral therewith is a hollow boss 26 that is located coaxlally with the hood and contains a shaft 21 that extends into the chamber 25 to carry the cutting disc 2|. The shaft 21 is provided with anti-friction bearings 28 and 29 that are arranged, respectively, in the inner and oter portions of the boss 26 and have their inner races seating against shoulders 30 and 3| on the shaft 21. A nut 32 threaded on the upper end of the shaft 21 clamps the inner race of the anti-friction bearing 29 securely against the shoulder 3|. f

'I'he cutting disc is disposed upon the portion 33 of the shaft lying below the shoulder 30, and

end to abut the cutting disc 2|. A nut 36 threaded upon the lower end of the shaft 21 clamps the cutting disc 2| fixedly against the flange 35 and presses the spacer 34 firmly against the anti-friction bearing 28.

The outer race of the anti-friction bearing 28 se'ats against a shoulder 31 in the hood 22 and the corresponding race of the anti-friction bearing 29 seats against a hollow plug 38 threaded into the upper end of the boss 26 to form a. closure therefor. Preferably, an .annular ange 39 is formed on the inner surface of the hood 22 to encircle the shaft 33 and a sealing member 40 is disposed in the space defined by the flange 39 and the spacer 34 to exclude dust from the anti-friction bearings and also to prevent the loss of lubricant from the anti-friction bearings into the chamber 25. i

Oni the side of the hood 22 whereon the boss 26'is `arranged is a tubular portion 4| that is formed integrally with the boss 26 and the hood 22 and is arranged substantially at a right angle to the boss 26 and, therefore, to the shaft 21. The outer end of the tubular portion 4| extends beyond the edge of the hood 22 and is provided with internal threads 42 to accommodate the threaded end 43 of a. handle 44 whereby the cutting tool may be held and guided with respect to the work. The handle 44 is securely fastened to the tubular portion by providing the end of said tubular portion with a -longitudinally extending slot 45 and placing a pinch bolt 46 in the wings 41 dening the slot 45 for clamping the end of the tubular portion firmly against the threaded end of the v handle 44.

` The portion of the handle 44 lying directly adjacent the tubular portion 4| constitutes a grip member 48 the outer end of which is attached to,

as by means of screws 49, and supports the casing 50 of a motor serving to drive the cutting disc 2 I. The motor is shown as being of a pressure fluid actuated type comprising a rotor 5| that is arranged in a chamber 52 in the casing 50 and carries vanes 53 against which pressure fluid acts for rotating the rotor. The pressure fluid serving this purpose is conveyed to the chamber 52 by a supply passage 54 and the expanded uid passes from the chamber 52 through exhaust passages 55 in the casing 50.

The pressure fluid supply for operating the rotor 5| is controlled by suitable valve mechanism only the operating lever 56 of `which is shown in a grip member 51 attached to and supported by the rearward end of the motor. Such pressure iluid may iiow through the grip member to the valve mechanism through a well known arrangement of ports and passages (not shown) from a supply conduit 88 attached to the grip member 51.

The means serving to transmit movement from the rotor to the cutting disc 2| and to the shaft 21 is arranged in the grip member 48 and the spectively, within the threaded end of the grip member and in the tubular portion 4| adjacent the boss 28.

A spacer 89, in the form of a sleeve, is interposed between the outer races of the bearings 61 and 88 to hold them suitably spaced with respect to each other, and shoulders 18 and 'lI within the tubular portion 4i and the grip member48 serve as abutments for the outer surfaces of said races.

On the end of the portion of the shaft 66 extending through the bearing 88 is a beveled gear 12 that meshes with a pinion 13 keyed to the shaft 21 for transmitting rotary movement to the cutting disc.

In order to expose a segment of the peripheral toothed portion of the cutting disc 2| for contact\ with the material intended to be cut the hood 22 and the cover 23 are each provided with a recess or notch 14 in corresponding portions of their outer edges. The notches 14 are of ample dimensions to permit a considerable segmento of the toothed portion of the cutting disc to be applied tothe work, and on the peripheries of the hood and the cover are prongs 15 the inner surfaces 'l of which coincide with the adjacent surfaces of the notches 14 and serve to support the weeds and brush intended to be cut in substantially the correct position with respect to the cutting disc 2|.

In order to prevent accidental contact with the teeth of the cutting disc, a guard 11 is provided for the portion of the cutting disc lying in the plane of the notch 14. The guard, which is of segmental shape, is arranged between the cutting disc 2| and the cover 23 and has a hub 18 that extends rotatably into a recess 19 in the inner surface of the cover 23. A hollow member 88 lying within the hub acts as a pivot for the guard and is secured to the cover 23 by a bolt 8| extending through the hollow member and the cover 28. A flange 82 on the inner end of the hollow member 80 overlies the hub 18 to retain said hub in the recess 19.

The guard 11 is preferably in the form of a thin plate and its outer ared portion is curved inwardly to a U-shape and the introverted wing 83 thus formed overlies the peripheral, toothed portion of the cutting disc 2|. l

To the end that the guard 11 may normally be drawn into and held in the plane of the notch 14 a tension spring 84 ls attached, at one end, to the hub 18 by a screw 85 and at its other end to a screw 88 in the inner surface of the cover 23.

The spring 84 is of considerable length and an end portion thereof lies in an external groove 81 in the hub 18 around which it is curved. The remaining portion of the spring 84 thus lies at aY tangent to the hub and will be considerably extended when the guard occupies the non-guarding position.

The means employed for shifting the guard to expose the teeth of the cutting disc is operated manually. It comprises a exible member, as for example a cable 88, which has a portion lying in the side of the groove 81 opposite to that occupied by the spring 84 and an end attached to the hub 18 by a screw 88. The cable 88 extends rearwardly through the chamber 25 in the direction of the handle 44 and through the wall of the cover 23 where it is attached as by means of a screw to an arm 9| of a lever 92.

The lever 92 is pivotally attached, as by means of pins or screws 93, to the overhanging end of the tubular portion 4| and lies directly beneath the grip member 48 so that it may be conveniently manipulated by a hand grasping said grip member. The distance that the guard 11 will move in the direction for uncovering the cutting disc depends upon the arc ,of movement of the ann 9| and the lever 92 is, therefore, so arranged and the cable 88 is of such length that when the lever 92 is rocked against the grip member 48 the guard 11 will be fully withdrawn from the plane of the notch 14. Movement of the guard 11 in an opposite direction is limited by a stop member 94 on the inner surface of the hood 22 and extending into the path of the wing 83.

The operation of the device is as follows: Whenever it is intended to out brush or the like, the grip members 51 and 48 are grasped to support the tool and apply its cutting disc to the work. The hand engaging the grip member 51 may also manipulate the lever 56 for controlling the power supply to the motor, and the hand grasping the grip member 48 may rock the lever 92 against said grip member. This movement of the lever, transmitted through the cable 88, will rock the guard 'E1 out of the protecting position.

The cutting tool is then advanced along the work which will be severed by the rapidly rotating disc 2|. During this operation the prongs 15 will serve to draw the brush into a more compact group and the prong on that side of the notch toward which the cutting teeth tend to bend the brush will support the brush in an upright position during the cutting thereof.

When the grip members 51 an 48 are released, as after the completion of cutting operation, the spring 84 which had been previously tensed by rocking the lever 92 against the grip vmember 48 will contract and rock the guard 11 into the plane of the notch or notches 14 until the side of the guard rests against the stopmember 94. The teeth of the cutting disc lying in the plane of the notches will then be fully covered and the chances of injury to the operator will be eliminated.

From the foregoing description it will be readily apparent that during' the idle periods of the cutting tool the cutting disc 2| will be fully guarded and that it may be instantly uncovered by pressing the lever 92 against the grip member 48. This is, moreover, a simple operation since it is merely necessary to place the hand below the lever 92 and lift the cutting tool, the weight of which causes the lever 92 to rock against the grip member 48 and remove the guard from the protecting position. lt will further be apparent that by placing the motor on one side and the cutting disc and its housing on the other side of the grip member 48 the tool will b e nicely balanced and may be conveniently held and ma.-

nipulated without causing undue fatigue to the ing a. U shaped opening extending from the edge operator. of said casing toward the axis of the saw to ex- We claim: pose a segment of said saw, a grip portion on the 1. A portable cutting tool, comprising a casing, a rotary toothed cutting disc in the casing, there being a recess in the casing to expose a segment of the cutting disc, a motor for driving the cutfting disc, a grip portion on the casing extending laterally of the axis of rotation of the cutting disc and connected to an end of the motor, a grip portion on the other end of the motor, means in one grip portion and the casing for transmitting'movement from the motor to the cut` a shaft and driving motor, a circular saw journaled at one end of the stem to rotate in a plane parallel to the shaft, a spade handle disposed at the opposite end of the stem, a saw casing havstem adjacent the casing, a guard portion pivoted on the casing and swingable into and out of the opening, a biasing spring for said guard portion, a manually operated lever at said grip portion and a connecting member between said lever and said guard portion.

3. A portable saw including a stem containing a shaft and driving motor, a circular saw journaled at one end of the stem to rotate in a plane parallel to the shaft, a spade handle disposed at the opposite end of the stem, a saw casing having a U shaped opening extending frornthe edge of the casing toward the axis of the saw to expose a segment of said saw, a grip portion on the stem between the casing and the motor, a guard portion pivoted on the casingl and swingable into and out of the opening and into the casing, a biasing spring for said guard portion, a manually operated lever at said grip portion and a connecting member between said lever and y said guard portion.

FRANCIS A.

HAROLD C', OLD 

